On January 10, 2013, New York City Mayor Michael Bloomberg announced new guidelines for the prescribing of opioid analgesics to patients being discharged from the city's emergency departments. The guidelines were developed by a panel of emergency physicians and are intended to reduce opioid addiction and overdose deaths while preserving access to opioids for patients in whom the benefits are expected to exceed the harms. Because most opioids are prescribed by primary care physicians, the introduction of these guidelines alone is unlikely to effect a large decrease in opioid-related harm. Nevertheless, it is worth considering why such guidelines are necessary and what complementary actions physicians, patients, and health authorities should take to address the increasing problem of opioid-related harm.